Energy Drinks

My stimulant of choice is coffee. I started drinking it in first-year university, and never looked back. A tiny four-cup coffee maker became my reliable companion right through graduate school. But since I stopped needing to drink a pot at a time, an entirely new category of products has appeared — the energy drink. Targeting students, athletes, and others seeking a mental or physical boost, energy drinks are now an enormous industry: from the first U.S. product sale in 1997, the market size was $4.8 billion by 2008, and continues to grow. (1)

My precious coffee effectively has a single therapeutic ingredient, caffeine. Its pharmacology is well documented, and the physiologic effects are understood. The safety data isn’t too shabby either: it’s probably not harmful and possibly is even beneficial. (I’m talking about oral consumption — no coffee enemas. Please.) In comparison, energy drinks are a bewildering category of products with an array of ingredients including caffeine, amino acids, vitamins, and other “natural” substances and assorted “nutraceuticals,” usually in a sugar-laden vehicle (though sugar-free versions exist). Given many products contain chemicals with pharmacologic effects, understanding the risks, signs of adverse events, and potential implications on drug therapy, are important.

So are energy drinks just candied caffeine delivery systems? Or are these syrupy supplements skirting drug regulations?

The Message

The ads are seductive. Who doesn’t want more energy? Who doesn’t want their mind and body “vitalized”? And don’t we have time-starved lifestyles? Initially envisioned for athletes, energy drinks are now marketed mainly towards teens and young adults, where uptake has been dramatic. Cross-promotion with extreme sporting events, and creating names like “Full Throttle,” “Rockstar,” and even  “Cocaine” burnish the “extreme” image. The market is now segmented further with products targeted at women, vegetarians, diabetics, celiacs, and more. However you identify yourself, there’s probably an energy drink developed with you in mind.

The Ingredients

Evaluating claims of efficacy and safety are complicated by the multiple formulations and versions of the products. Most energy drinks contain these ingredients:

Ginseng is often claimed to have remarkable properties, from preventing colds to acting as an immune “booster”, but there’s actually little evidence to suggest it has any of these effects. Studies looking specifically at performance effects have not been impressive. (2) Furthermore, the doses that have been studied significantly exceed the amounts that are found in energy drinks. At low doses ginseng seems safe, but there’s not a lot of long-term data to reassure us. (3)

Taurine is an amino acid that is is plentiful in our diets, and can also be endogenously manufactured. It’s involved in an array of physiologic functions. What’s not clear is if exogenous taurine supplements have any meaningful effect on subjective or objectively measures of “energy” or performance. There are limited data evaluating taurine in combination with caffeine, but high quality evidence is lacking. Taurine does seem to be reasonably well tolerated, however, with few adverse events reported or expected. (3)

Glucuronolactone is another natural ingredient of food for which there’s no evidence of deficiency, nor any evidence that supplementation improves energy level. Consumption at the levels present in energy drinks is considered safe.

Bitter Orange is the peel or oil from Seville oranges. It became a popular ingredient in supplements after ephedra was pulled from the U.S. market. A natural source of epinephrine-like compounds, it shares the same adverse effect profile, with links to serious events such as syncope, heart attacks, colitis, and stroke. There’s no persuasive evidence demonstrating bitter orange provides any energy boost, particularly at the low levels present in energy drinks. However, given bitter orange is usually combined with other stimulants, the true pharmacologic profile, and consequent adverse effects, may not be clear. (3)

Caffeine and guarana (a natural source of caffeine) are the most relevant ingredients in energy drinks. Caffeine has a variety of physiologic effects, and while it appears to have value improving endurance and reducing fatigue during sustained physical exercise, its role as a cognition booster seems much more tenuous. It also seems to improve the effectiveness of analgesics, and may possibly have its own analgesic properties. In general caffeine has a reasonable safety profile at moderate doses. (3)

While total amount of caffeine in an energy drink may not be listed, as natural sources may not be included in the nutritional information, coffee has more caffeine than many energy drinks. A 16 oz “grande” coffee at Starbucks has 320mg of caffeine; the 20oz “venti” has 400mg. (For Tim Hortons lovers, there’s about half that much caffeine in your double-double). In comparison, a Red Bull has 151mg/16 oz, Monster Khaos has 150mg/16oz, and Rockstar Punched has 160mg/16oz. And a 573mL can of Coca Cola (19oz) has a piddly 62mg. If you accept that caffeine is worth consuming, then energy drinks are clearly not the best source. Even factoring in the caffeine from guarana, coffees still appears to be the caffeine king. (CSPI has a nice compilation of the caffeine content of different beverages.)Besides, there’s always Nodoz.

Vitamins are in many of the energy drinks: especially combinations of the B vitamins, like cyanocobalamin (B12), niacinamide (B3), pantothenic acid (B5) and pyridoxine (B6). Vitamin C is also common. In the absence of a deficiency, there isn’t any persuasive evidence to suggest that supplementation has meaningful effects on “energy”, however defined. (3) Even long term use of the B vitamins doesn’t look promising for cognition.

Sugar is the major sweetener in energy drinks, though sugar-free versions exist. Speaking strictly in terms of chemistry, as a carbohydrate, sugar is the only actual energy in an energy drink. (The “calorie free energy drink” ads make me laugh out loud.) The sugar content of most products seems largely similar to colas and other soft drinks. So if you want to carb-load, there’s no particular advantage to the energy drinks – sugar is sugar, and calories are calories.


Side effects related to energy drinks appear to be largely due to the caffeine content. Thresholds are difficult to predict, given that tolerances to caffeine can vary. In general, the amounts of taurine, guarana, and other components are felt to be below the level necessary to cause noticeable adverse effects.(2) While there have been serious adverse events reported with energy drinks including seizures and sudden death, clear causation has not been established.

Probably the biggest concern related to energy drinks is their consumptions by youths and adolescents, where caffeine’s effects are less well understood. Sugar and caffeine consumption are probably best minimized in this population, yet it’s clear that this is the target consumer.

The combination of energy drinks with alcohol — they are popular mixers — has been linked to a suppression of the traditional intoxication effects.There’s controversy over the sale of the deliberate combinations of the two ingredients, and some regulators have taken action to stop the sales of some products.


Regulation of energy drinks varies by country. From an international perspective, the United States has one of the least regulated marketplaces. (1) Caffeine limits that apply to cola drinks do not apply to energy drinks. In Canada, some energy drinks are federally approved as natural health products. For example,  the authorized recommended use for Red Bull is:

Developed for periods of increased mental and physical exertion, helps temporarily restore mental alertness or wakefulness when experiencing fatigue or drowsiness.

The product has a specific caution not to consume more than 500mL (2 cans) per day, and that it is not recommended for children, pregnant, or breastfeeding women.

Given their noveltly in the market, and their growing popularity, expect regulatory approaches to vary around the world. Products like Red Bull have been subject to regulatory restrictions and even bans in some European countries.


Neither innocuous nor toxic, energy drinks seem safe for adults when consumed in moderation. There’s no convincing evidence to back up the cognitive or athletic performance enhancement claims attached to the category, or to specific products. Despite the impressive lists of ingredients and slick marketing, these products are essentially caffeine delivery vehicles, most of which come loaded with sugar. The incremental risk from the other ingredients isn’t well understood, but is probably small when consumed occasionally.

So go ahead and enjoy your Red Bull. But when that liquid candy stops appealing to you, I’ve got some shade-grown, bird-friendly, passive-organic, fair-trade, home-roasted coffee for you to try.


  1. Heckman, M., Sherry, K., & De Mejia, E. (2010). Energy Drinks: An Assessment of Their Market Size, Consumer Demographics, Ingredient Profile, Functionality, and Regulations in the United States Comprehensive Reviews in Food Science and Food Safety, 9 (3), 303-317 DOI: 10.1111/j.1541-4337.2010.00111.x
  2. Clauson, K., Shields, K., McQueen, C., & Persad, N. (2008). Safety issues associated with commercially available energy drinks Journal of the American Pharmacists Association, 48 (3) DOI: 10.1331/JAPhA.2008.07055
  3. Natural Medicines Comprehensive Database. Subscription required to view.

Posted in: Herbs & Supplements, Nutrition, Politics and Regulation

Leave a Comment (27) ↓

27 thoughts on “Energy Drinks

  1. BillyJoe says:

    Some of us over-react to caffeine and cannot drink ordinary coffee without developing palpitations, tremors, agitation, and insomnia.
    And weak coffee is undrinkable.
    Fortunately there are now caffeine-free coffee beans.

  2. jb_pt says:

    Is there any concern to the B vitamin content in some of these energy drinks? Some have upwards of 250-500% RDA in one serving. Would a few cans reach toxicity levels?

  3. I like the article, but it needs this quote. “”This coffee falls into your stomach, and straightway there is a general commotion. Ideas begin to move like the battalions of the Grand Army of the battlefield, and the battle takes place. Things remembered arrive at full gallop, ensuing to the wind. The light cavalry of comparisons deliver a magnificent deploying charge, the artillery of logic hurry up with their train and ammunition, the shafts of with start up like sharpshooters. Similes arise, the paper is covered with ink; for the struggle commences and is concluded with torrents of black water, just as a battle with powder.”
    — Honoré de Balzac

    Like Balzac, I feel that the caffeine in coffee stimulates my creativity and clarity of thought. Sadly, once you are an addict (like me) you no longer feel creative or stimulating with the coffee, you only feel stupid and dull (with a massive headache to boot) without the coffee.

    Energy drinks? psffft! They are to a quality cup of coffee (latte, espresso…) as a bottle of Boone’s Farm Strawberry Hill is to a lovely Pinot Noir.

  4. S.C. former shruggie says:

    I suspected these energy drinks had more hype on their labels than the evidence supported. Thanks for the post. I’ll stick to my ginseng-free, non-vitamin coffee.

  5. aeauooo says:

    I hadn’t paid much attention to energy drinks until I noticed a bottle of “NOS” in the grocery store. Recognizing NOS as the abbreviation for nitric oxide synthase, I jokingly thought to myself, “What, does it contain arginine?”

    It does.

  6. ConspicuousCarl says:

    I like diet Red Bull, but sometimes I get a little annoyed that it has all of that nonsense along with it. I would totally buy a can of caffeine without all of the hype and extra ingredients.

  7. Scott says:

    The commercials for “5-hour energy” amuse me. “Oh, it’s got all this wonderful stuff that’s in avocados (or whatever). And oh yeah, as much caffeine as a cup of coffee.”

    Gee, which one of these is more likely to be the active ingredient?

  8. Anthro says:


    Decaf has been around for as long as I can recall, and I’ve been an avid coffee/espresso drinker (roast and grind my own fair-trade, shade-grown beans) for 35 years. It is my understanding, however, that decaf has almost half the caffeine of regular coffee–it is NOT caffeine FREE. I only drink decaf after about 2 pm, but not in the evening, for this reason, as even small amounts of caffeine keep me awake.


    I love the Balzac quote–thanks for sharing. I’ve seen your comments elsewhere, as well, and enjoy your perspective.


    My question is, WHY are people willing to PAY for a can of sugar water? This is at least as dumb as paying for bottled water with all its environmental shortcomings. Why do people have to have something to drink every other minute of the day? I have a latte in the am and a decaf in the afternoon and some tap water a couple times a day–most always consumed at home. Am I missing something?

  9. tmac57 says:

    Anthro-“I have a latte in the am and a decaf in the afternoon and some tap water a couple times a day–most always consumed at home. Am I missing something?

    A couple glasses of wine perhaps? (caffeine free of course)

  10. BudS says:

    I had hoped to see some discussion about consumption of “empty calories” and glycemic effect. At least caffeine, as far as I know, is safe from this effect.

  11. BillyJoe says:


    “Why do people have to have something to drink every other minute of the day?”

    I think they are in morbid fear of dehydration.

    There is an overload of health warnings reminding people of the perils of dehydration. It is overkill. Very few people die of dehydration, including athletes. On the local 2.5km circuit trail where there’s a tap at the starting point, every second person carries a water bottle with them! And they’re walking!! Even when running, you need a drink only every 5km or so.

    The situation has become so bad that people are now dying of over-hydration which cause death through electrolyte disturbance. Recently an 18 year old lad died on the Kokoda Trail. Everyone assumed he’d died of dehydration, but the autopsy report showed the opposite. He’d actually drunk himself to death.

  12. koikuri says:

    @Anthro and BillyJoe:

    I’m one of those people who needs to have something to drink around all the time. If I don’t, I get headaches, feel lightheaded, have chills/hot flashes, and, you know, some unpleasant variations in urine too. I have assumed this is related to dehydration, as every single one of those symptoms goes away when I drink more non-diuretic fluids.

    If it’s not dehydration, and there’s a better solution than constant fluid intake, I’d genuinely love to hear it. Needing to drink every couple of hours is kind of a bummer on long car rides, airplanes, and in many work environments. (And I hate that I have to count my coffee as the equivalent of no beverage because of the caffeine.)

  13. @ Anthro, thanks! .

    Also, regarding water consumption. I heard on an environmental radio show a while back that every bottled water sold uses an additional bottle (16oz?) of water in manufacturing (creating the plastic, bottling etc). Pretty ridiculous when you can use a refillable bottle and tap water in most areas.

    My husband is crazy about taking water for the kids with us everywhere, running errands, going to the mall, a very short hike. I think that I am finally beginning to break him of the habit with my “We aren’t taking a 10 mile hike in the Serengeti are we?” comments. At school, I’ve noticed that the kids all seem to have a water bottle on their desks. Seems like more of a detraction than anything else.

    That said, I actually have to force myself to drink adequate water. (water, yuck, I don’t get it.) I’ve had to go to the ER a couple of times for IV when dehydrated due to flu. So I should shut up. I’m not a great role model. :)

  14. JM Shep says:

    As a recent college graduate who worked over 40 hours/wk between my paying job and a lab job while attending school full-time, I am quite familiar with energy drinks. I guess for a long time I thought they had more caffeine than a cup of coffee, but somewhere along the line I did find out they were about the same.

    Coffee doesn’t always sit well with me after my (at this point) 2-mugs per day, so if I need a boost I’ll reach for an energy drink. I almost always opt for the sugar-free or low-cal (Rockstar has one of each, and they’re totally different), but there were/are times, especially in college, where I opted for the sugary versions specifically to ride the sugar high until the caffeine kicked in. The healthiest choice? Maybe not, but when were college kids known for their good health habits? Plus, I think the author is right when he says, “energy drinks seem safe for adults when consumed in moderation.” I said I would cut back when I graduated, and I did.

  15. koikuri – “I’m one of those people who needs to have something to drink around all the time. If I don’t, I get headaches, feel lightheaded, have chills/hot flashes, and, you know, some unpleasant variations in urine too.”

    Don’t mean to be intrusive and I’m not a medical person, but you have been check out for diabetes? Right?

  16. Harriet Hall says:


    Have you considered the possibility that you might have developed a conditioned response? Some of the symptoms you describe are not those of typical mild dehydration (chills and hot flashes?).

    Also, coffee is not “the equivalent of no beverage.” That’s a myth. Caffeine does have a mild diuretic effect, but it is counterbalanced by the water. Especially if you customarily drink coffee, it counts as part of your fluid intake, not as a diuretic.

  17. Harriet Hall – “That’s a myth. Caffeine does have a mild diuretic effect, but it is counterbalanced by the water. Especially if you customarily drink coffee, it counts as part of your fluid intake, not as a diuretic.”

    Don’t tell me that. You’ll only enable my unhealthy rationalizations. :)

  18. nybgrus says:

    Hey Carl! Check out thinkgeek’s caffienated drinks section:

    Bawls is a simple drink with caffeine and that is about it. Granted, it only has 80mg/10z but they have stronger stuff. They even have caffeinated gum. When I started working nights in the ER I used to chew a piece or two to pick me up.

  19. rmgw says:

    “peel or oil from Seville oranges.” Take this in the form of British marmalade on your toast, add coffee and you have the perfect breakfast! Or are we now to avoid marmalade on the grounds that bitter orange peel induces all sorts of bad things?

  20. rmgw “Take this in the form of British marmalade on your toast, add coffee and you have the perfect breakfast! Or are we now to avoid marmalade on the grounds that bitter orange peel induces all sorts of bad things?”

    Le Papillon in Dominica makes a killer rum punch that I was told uses bitter orange (amongst other things). Marmalade with toast or Homemade Rum Punch….? Choose your poison, I guess.

  21. weatherwax says:

    I don’t like coffe, and always got my caffiene from sodas. Yes, even for breakfast. One of the things I learned in college was that while it would keep me awake, it wouldn’t keep me alert. On several occasions I OD’d with the intention of pulling an all night study session, only to find I couldn’t concentrate on the studies, and would be on the verge of dozing off. When I gave up and went to bed I’d lie there with my eyes wide open. Give up and go back to studying, only to find myself dozing off again.

    I don’t have any interest in energy drinks, but allot of my co-workers really love them. I ususally work in forestry related jobs, outdoors and energy intensive, so watching my co-workers slam them when it was already hot and dry really scared the crap out of me.

  22. BillyJoe says:

    Harriet Hall,

    “Also, coffee is not “the equivalent of no beverage.” That’s a myth. Caffeine does have a mild diuretic effect, but it is counterbalanced by the water. Especially if you customarily drink coffee, it counts as part of your fluid intake, not as a diuretic.”

    If the diuretic effect of the caffeine in coffee is counterbalanced by the water in coffee, doesn’t that mean that drinking coffee IS the equivalent of no beverage?

    When in doubt, google:
    I don’t know if this site is reliable but the explanation for the coffee myth (if it is a myth) makes sense to me:

    The caffeine in coffee has a mild diuretic effect, increasing the frequency of urination but not the amount of fluid passed. For many years health and exercise experts thought that, as a consequence, coffee and other caffeinated beverages promoted dehydration and didn’t count as a source of fluid in the diet. We now know this is not true and there is no scientific evidence to support these views. Caffeine in fact is no more a diuretic than water.

  23. BillyJoe says:

    Come to think of it, that doesn’t make sense either.

    If coffee “increases the frequency of urination, but not the amount of fluid passed” then it is not actually a diuretic, which is defined as “increasing the volume of the urine excreted, as by a medicinal substance” (

    But reading further:

    Professor Lawrence Armstrong, an avid runner and well respected scientist , decided to review the scientific literature to see whether abstaining from coffee and other caffeinated drinks was scientifically justifiable. In his published report he concluded:

    · After drinking a caffeinated drink, the body does retain most of the fluid ( up to 84% has been reported in some studies)
    · Moderate consumption does have a mild diuretic effect, but the overall effect is very similar to water.
    · Regular consumers of caffeinated drinks have a higher tolerance to the diuretic effect.

    Medscape agrees:

    A variety of investigations have been reviewed spanning more than 75 yr. The evidence indicates that consuming a moderate level of caffeine results in a mild increase of urine production. Although this diuresis may (240-642 mg of caffeine) or may not (<240 mg) be significantly greater than a control fluid (0 mg of caffeine), there is no evidence to suggest that moderate caffeine intake (<456 mg) induces chronic dehydration or negatively affects exercise performance, temperature regulation, and circulatory strain in a hot environment. Caffeinated fluids contribute to the daily human water requirement in a manner that is similar to pure water.

    An average cup of coffee contains 75mg caffeine (range 65-110mg), so drinking 6 cups of coffee per day has the same effect on hydration as drinking the the same volume of water.

  24. Calli Arcale says:


    “peel or oil from Seville oranges.” Take this in the form of British marmalade on your toast, add coffee and you have the perfect breakfast! Or are we now to avoid marmalade on the grounds that bitter orange peel induces all sorts of bad things?

    I don’t think you’ll be getting quite as much of it in marmalade. ;-)

    I drink an energy drink, sort of — I drink Mountain Dew Voltage. It does contain ginseng, but I don’t think it has any significant effect other than flavor — it’s kind of a gingery flavor, so overall the drink tastes like a fruity ginger ale. And I like ginger ale, and my citrus allergy was beginning to give me problems with regular Mountain Dew, so I love the stuff. (I kind of wish they hadn’t decided to dye it blue, though. Peculiar color.)

  25. Calli Arcale “(I kind of wish they hadn’t decided to dye it blue, though. Peculiar color.)”

    Why do they do that? I’ve learned about the naturalistic fallacy from SBM and all, but still I can not take blue drinks*…that color just does not seem healthy to me.

    *except when it involves alcohol, then blue seems fun and exotic, go figure.

  26. Deeba says:

    Nice to have my suspicions confirmed- I have friends who swear energy drinks are better than coffee because of B vitamins and/or taurine. I do drink them, but I’ve never noticed a difference in the effects of the cup of coffee I have at 2pm and the energy shooters at 2am. Just different ways to get a caffeine fix.

  27. shawmutt says:


    You stated “…decaf has almost half the caffeine of regular coffee–it is NOT caffeine FREE.”

    I was going to tell you how wrong you were, but now I need to change my answer. According to a study done by the NIH,, decaf coffee contains anywhere from 0-10% of the caffeine of regular. It’s lower than you stated, but higher than I originally thought.

    I always thought decaf meant 99% caffeine free, but the evidence shows otherwise.

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